[BUILD] includes order breaks OpenBSD build

Jeff Buchbinder reported that OpenBSD build broke on compat.h,
and that this patch fixes the issue.
diff --git a/include/common/compat.h b/include/common/compat.h
index 3c939ce..9eecdfb 100644
--- a/include/common/compat.h
+++ b/include/common/compat.h
@@ -23,8 +23,8 @@
 #define _COMMON_COMPAT_H
 
 /* This is needed on Linux for Netfilter includes */
-#include <sys/socket.h>
 #include <sys/types.h>
+#include <sys/socket.h>
 #include <common/config.h>
 #include <common/standard.h>